Guo et al. [10] performed a quantitative analysis on the contrast patterns of the dynamic MRI images of ACTH-producing pituitary adenomas and found that the tumour prepeak slope (referring to the measure of the tissue perfusion rate or speed reaching peak intensity in the enhancement curve) of ACTH-producing adenomas was significantly lower than that of non-functioning adenomas. The gene discussed is POMC; the disease is adenoma.